Social network services (SNS) refer to services by which people may strengthen existing relationships with others and may make more personal connections based on the web. The SNS may provide a service for classifying people into specific groups, a service for providing a means by which the users can contact their friends, or the like. Initial social networks were generalized online communities in which groups or people who are interested in a particular topic sharing exclusive services in which the users get together and chat to each other in chat rooms or the users post personal information or articles on their personal home pages. Afterwards, with the provision of the SNSs that allow the user to share his/her individual interests and personality and that can attract tens of millions of unique service users, the SNSs have been productively used to share business and a variety of information. The SNS may provide a means by which the users can contact each other through e-mails or instant messenger services. The SNS enables a one-person media and a one-person community to help the sharing of personal information and communicate with each other. In addition, since the SNS enables users who have the same interest or social background to make personal connections and exchange information with each other, the SNS users may be provided with highly reliable information.